Riyad us Saliheen: Hadith 1310

The Prophet (ﷺ) said, "No one who has entered Jannah will desire to return to this world even if he should be given all that the world contains, except a martyr. For he will yearn that he should return to the world and be killed ten times on account of the dignity that he will experience by virtue of his martyrdom."

Another narration is: "On account of the excellence and distinction, he will experience as a result of martyrdom."

[Al-Bukhari and Muslim].